RFR 8229898 [lworld] Enable C1 by default

Ioi Lam ioi.lam at oracle.com
Tue Sep 10 15:50:55 UTC 2019


https://bugs.openjdk.java.net/browse/JDK-8229898
http://cr.openjdk.java.net/~iklam/valhalla/8229898-enable-c1-default.v01/

We have been testing with -XX:+EnableValhallaC1 in mach5 for a couple of 
weeks and don't see any failures. So this patch is to enable C1 by 
default (same as the usual JDK)

(I'll push after a new LW2 update release is done).

+ By default both C1 and C2 are enabled, and tiered compilation is enabled
+ The EnableValhallaC1 flag is removed
   + To use C1 only: -XX:TieredStopAtLevel=1 -XX:+TieredCompilation
   + To use C2 only: -XX:TieredStopAtLevel=4 -XX:-TieredCompilation

I adjusted the test cases that are specific to C1/C2 testing to use the 
flags the new way.

I also fixed a bug in ValueTypeTest::parseOutput to properly parse the 
-XX:+PrintCompilation output (with tiered compilation, an extra number 
is printed to indicate the tier level). Previously, (due to this parsing 
bug) we disabled VERIFY_IR when C1 is enabled.

@Tobias -- I had to add this. I think when C1 is enabled, the number of 
counted loops could be different

  541       if (TieredCompilation) {
  542           // FIXME: TestLWorld.test88 fails with "expected 4 to 
equal 2"
  543           continue;
  544       }

Thanks
- Ioi


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